1. Field of the Invention
The present invention relates to ground engaging tools, also known as opener assemblies, for agricultural drill systems. In particular, the present invention relates to opener assemblies that can be used under till and no-till conditions. The opener assembly is mounted on a shank that extends from the frame of the drill system. As the drill system is conveyed by a tractor or other off-road vehicle, the opener assembly is lowered to engage the ground and forms a furrow in the ground into which seed and other media are placed. In order to form the planting furrow and to seed in one pass, the opener assembly is in communication with a seed and other media distribution system that provides a metered flow of seeds and other media to the opener assembly.
2. Description of Related Art
Efficient and economic use of resources is a critical concern of farmers during planting season. The optimal time period or window for planting is limited and sometimes is as brief as a few days. If planting is done outside of this window, yields may be adversely affected. Though time is always of the essence, the quality of seed and material handling must be maintained to provide desirable rates of germination and plant growth.
Flexible equipment assists the farmer in making the best use of time and other resources. With limited time frames for optimal planting conditions, a farmer routinely wants to minimize equipment down time that occurs, for example, when equipment must be changed to accommodate different crops and field conditions. Down time is minimized when the farmer can use equipment that is flexible so as to handle multiple seed types and a wide range of field conditions.
Depending on the crop, the soil, planting practices and weather conditions, a farmer may choose to till or not to till a field before planting it. For example, the farmer may need to incorporate chemicals, dry out the soil, or remove weeds. Turning over and tilling the soil will create warmer soil conditions for the seed, while soil that is not tilled will be cooler in temperature. If the field is to be tilled, it may be desirable to use a drill system that can till and plant in one pass. The planting portion of the process, including forming the furrow or trench into which the seed is deposited, is done by what is known in the art as a ground engaging tool or an opener. Historically, those engaged in agricultural operations located in different regions of the country have grown accustom to using particular types of opener assemblies for planting particular types of crops.
For example, disc openers are flat and round and have a sharp blade edge for cutting through the ground. Disc openers are pulled through the ground and, as they rotate like wheels across the ground, they cut a furrow or trench into which seed can be deposited. Disc openers have conventionally been used to plant row crops, like corn. Row crops include corn, sunflower, and some varieties of soybean; row crops are typically characterized as those crops where the rows of seed are spaced apart by some distance, for example 15 inches or more. Though typically used for row crops, disc openers can also be used for solid seeding. Solid seeding is usually performed for cereal crops and results in a seed pattern that is ribbon-like such that the seeds are dropped closely together. Solid seed crops maximize the surface area usage of soil because they do not have "dead space" between rows as occurs with row crops. Solid seeding is generally understood by farmers to describe any seed pattern where the "rows" are spaced less than 15 inches apart. There also are grain drills for wheat and other cereal crops that are comprised of discs spaced as little as six inches apart; however, there are physical limitations on how closely discs can be located next to each other. While disc openers typically have good seed depth control, they are not rugged in terms of being able to handle mud and trash, such as rocks, sticks, and organic matter from the previous crop in the field and they require more maintenance.
The alternative to a disc opener is an opener assembly that is mounted on a shank. Shank mounted openers are more flexible than disc openers in terms of the soil conditions that they are able to handle. For example, shank mounted openers can handle more mud and trash flow than disc openers. Further, they require less maintenance for operation. Shank mounted openers can be used with both till and no-till planting. The combination of a shank seeder with a sweep allows one pass tilling and planting.
After the trench has been formed by either a disc or shank mounted opener and prepared for seed growth, the assembly must provide for delivery of the seed to the trench. This is typically performed by a seed boot, of which numerous configurations are known. Regardless of the design used, the objective of the seed boot is to provide a location where the seed can be delivered to the trench. Accuracy and control of the rate of seed delivery is checked with seed sensors that are mounted high enough on the seed boot to be protected from soil and debris. Some known opener assemblies further include a media delivery tube for dispensing beneficial media, including fertilizers, into the trench at the same time that the seed is planted.
Though a variety of opener assemblies are known, there remains a need for an opener having improved versatility and lower maintenance needs. Further, there remains a need for an opener assembly that provides for an improved seed environment. The configurations of currently available opener assemblies may be limited to dispensing only one beneficial medium to assist the germination and growth of the seeds. Therefore, there remains a need for an opener assembly in which the seed sensor can more accurately measure the rate of seed delivery without damage to the seed or the sensor and in which more than one beneficial medium can be delivered into the trench at the same time the seeds are planted.